package com.exedosoft.plat.util;

public class Base64Converter
{

     public static final char[] alphabet = {
         'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', // 0 to 7
         'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', // 8 to 15
         'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', // 16 to 23
         'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', // 24 to 31
         'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', // 32 to 39
         'o', 'p', 'q', 'r', 's', 't', 'u', 'v', // 40 to 47
         'w', 'x', 'y', 'z', '0', '1', '2', '3', // 48 to 55
         '4', '5', '6', '7', '8', '9', '+', '/'}; // 56 to 63

     public static String encode(String s)
     {
         return encode(s.getBytes());
     }

     public static String encode(byte[] octetString)
     {
         int bits24;
         int bits6;

         char[] out
             = new char[ ( (octetString.length - 1) / 3 + 1) * 4];

         int outIndex = 0;
         int i = 0;

         while ( (i + 3) <= octetString.length) 
         {
             bits24 = (octetString[i++] & 0xFF) << 16;
             bits24 |= (octetString[i++] & 0xFF) << 8;
             bits24 |= (octetString[i++] & 0xFF) << 0;

             bits6 = (bits24 & 0x00FC0000) >> 18;
             out[outIndex++] = alphabet[bits6];
             bits6 = (bits24 & 0x0003F000) >> 12;
             out[outIndex++] = alphabet[bits6];
             bits6 = (bits24 & 0x00000FC0) >> 6;
             out[outIndex++] = alphabet[bits6];
             bits6 = (bits24 & 0x0000003F);
             out[outIndex++] = alphabet[bits6];
         }

         if (octetString.length - i == 2) 
       {
             bits24 = (octetString[i] & 0xFF) << 16;
             bits24 |= (octetString[i + 1] & 0xFF) << 8;

             bits6 = (bits24 & 0x00FC0000) >> 18;
             out[outIndex++] = alphabet[bits6];
             bits6 = (bits24 & 0x0003F000) >> 12;
             out[outIndex++] = alphabet[bits6];
             bits6 = (bits24 & 0x00000FC0) >> 6;
             out[outIndex++] = alphabet[bits6];
             out[outIndex++] = '=';
         }
         else if (octetString.length - i == 1) 
       {
             bits24 = (octetString[i] & 0xFF) << 16;

             bits6 = (bits24 & 0x00FC0000) >> 18;
             out[outIndex++] = alphabet[bits6];
             bits6 = (bits24 & 0x0003F000) >> 12;
             out[outIndex++] = alphabet[bits6];
             out[outIndex++] = '=';
             out[outIndex++] = '=';
         }

         return new String(out);
     }
     
     public static void main(String[] args){
    	 
//    	 5Zu96ZmF5bGV5Lya6YCa55+l
//    	 ufq8ytW5u+HNqNaq
    	 String tem = "国际展会通知";
    	 System.out.println("Base64::" + StringUtil.encodeBase64(tem));
    	 
    	
    	 
    	 System.out.println("THIS:::::" + Base64Converter.encode(tem));
    	 
      	 System.out.println("THIS22222222:::::" + Base64Converter.encode(StringUtil.encodeBase64(tem)));
      	 
      	 tem = StringUtil.newInstance().encodeFromISO2UTF(tem);
      	 
    	 System.out.println("Base64::2222222::::" + StringUtil.encodeBase64(tem));
    	   
      	 	 
     }
}
